FIGURE 2.

Fragmentation analysis of released glycans from IgG. Example fragmentation spectra are shown for EndoS released glycans (A, B, C, D, and E) and PNGase F released glycans (F, G, H, I, and J) from serum IgG. Fragmented glycans are represented using Oxford glycan nomenclature (46) combined with the color scheme of the Consortium for Functional Glycomics as previously implemented (20, 47). Fragments are labeled following the Domon and Costello nomenclature (28). The spectrum shown in D contains a contribution from ions (particularly the ions at m/z 262, 424, and 951) derived from another adduct of the glycan of composition Man₃GlcNAc₃ appearing at the same mass. Only partial separation of the ions from these compounds was achieved by ion mobility.